Wednesday, January 30, 2013

Beyond green building: Alex Wilson on resilient design

Alex Wilson

After Hurricane Sandy, preparing New York for future disruptions became a common topic in some government and civic circles. Municipal Art Society convened an excellent conference in January. (Some of the videos are available online.) Conversations mostly gravitated to future hurricanes and floods, although climate change will bring a range of potential disruptions and extreme weather events. So far, calls to sharply lower our carbon emissions to reduce the scale of future climate disruption don't seem to be getting much traction. However, for NYC civic leaders to take a serious look at post-Sandy preparedness is a giant step forward. The Bloomberg Administration recently launched the NYC Special Initiative for Rebuilding and Resiliency, which encompasses several interagency task forces. One is the City’s new Building Resiliency Task Force, which will look at both the direct effects of extreme weather on buildings, such as flooding or wind damage, and indirect effects caused by infrastructure outages like loss of electricity and water. One member of that task force is Alex Wilson, a leading green building publisher for thirty years, as the founder and executive editor of BuildingGreen. In addition to authoring several books and hundreds of articles, he served as executive director off the Northeast Sustainable Energy Association. Alex is one of those taking green building to a deeper level by incorporating resilience to accelerating social and ecological changes. At a recent Green Drinks NYC event, he spoke about his newly created Resilient Design Institute (RDI) and what we can do in NYC. Alex got involved in building resilience after Hurricane Katrina, working in Gulf Coast communities not just to restore them to their previous condition, but to prepare them for future events. Alex noticed that older homes, with their vernacular architecture, were better adapted to deal with problem conditions. The broad wrap-around porches and open room design of older homes built before air conditioning became universal in the 1940s were well-suited for coping with heat, and supplying natural ventilation. If electricity is cut off, the old-fashioned houses are much more livable.

Alex began combining the best of traditional design methods and contemporary science and materials to build structures that are livable even without fuel or electricity. For five years, he called it passive survivability and as he put it, failed miserably. Then he shifted to a more upbeat term: resilient design. The historical data is showing huge increases in intense storm events, especially in the Northeast and Midwest. With our insufficient progress in reducing carbon emissions, climate related disasters will keep increasing. The green building community will increasingly have to meet the need for resilient design, learn how to build net zero energy homes, and to apply those design principles to entire communities. Environmentally aware folks will get this instantly, but an appealing message for non-environmentalists can simply be that these homes will keep their family safe. “Even Rush Limbaugh could like that.”

FloodingNew England towns like Brattleboro were flooded when normally placid streams running through them were inundated by torrential rainstorms. To minimize future flooding, communities directing streams through single three-foot culverts could replace them with three four-foot culverts. Whether in small communities or in NYC, builders will have to use materials that don’t become useless or toxic after they get wet. It’s common to fixate on flooding, but that’s just one point of vulnerability.Wind eventsEven light frame residences can be engineered to resist uplift forces of strong wind events. In Dade County, Florida, county codes require extra tie-downs connecting structural elements. In Oklahoma, it’s common to build small hurricane safe rooms of reinforced concrete, partly underground.High temperaturesThe less heat is absorbed into the house, the less energy will be required to meet cooling needs. Wrap-around porches on south and west sides of a house shade the first story with broad roof overhangs, preventing heat absorption. Roofs with highly reflective coatings absorb less heat, as do windows with low emissive glazing. While venetian blinds on the inside of a window are helpful, it’s better to prevent sunlight even passing through the glass. Two approaches are exterior shades covering the windows, or manually adjustable sun shutters. For NYC buildings, external screens can be mounted over west side windows and angled to minimize how much summer sunlight enters the window. Water shortage and droughtClimate change effects in the northeast are expected to include more rain, along with generally more erratic weather. The south, west and Midwest are already getting more frequent and severe droughts. (Check the US Drought Monitor for regional drought forecasts.) Buildings in those areas can minimize their water requirements by installing not just low-flush toilets, but composting toilets and waterless urinals. Grassy lawns do well in the water-rich northeast. For drier areas, xeriscaping - landscaping with desert plants and less-thirsty native plant species – and even gravel lawns are probably a better fit. Rooftop rain harvesting or water catchment is a good idea anywhere, even in NYC, but easier to promote where there is greater public concern about drought. Where rural houses get water via an electric pump, adding a manual pump ensures consistent water supply even if the power goes out. BlackoutsHow can buildings be designed to stay warm or cool for a long time even if electricity is cut off? Droughts can indirectly cause power outages, as about 90% of our power plants require cooling water to function. Installing very high levels of insulation, above what’s currently encouraged, is the answer. While triple-glazed windows are considered to be a premium in the US, they’ve been standard in Swedish building codes since the 1970s. Most US homes with solar photovoltaic panels are not automatically protection for electric outages, as they’re designed to operate in connection with the power grid. PV systems have to be customized to operate as an island from the grid before they can provide power security in the event of a grid outage.Food securityNew Yorkers don’t usually think about where our food comes from. We will when droughts affect Midwest grain production, or yield of fruits and vegetables from California’s Central Valley. That’s a good reason to promote growing more of our food within New York State, and even within NYC, as we’ve been exploring lately on this blog. Alex points out that buildings and power plants can capture waste heat and run it through greenhouses and aquaponic systems, which combine production of plants and fish.

Existing buildingsExperts can design new buildings to very high standards of efficiency and resilience, which are far beyond the vast majority of the current stock of standard NYC buildings. Resilient building retrofits are very hard and very expensive.

For houses and multi-family buildings, about four inches of additional insulation must be applied, either to outside, using mineral wool, or the inside, using foam. How the building handles moisture is critical. If water gets in from the outside, or moisture condenses from the inside, it can cause mold, or damage building structures. Roof overhangs are essential to keep rainwater away from exterior walls. Moving equipment from basements to second floors or the roof is obviously a challenge, as is applying these approaches to big commercial buildings.The commercial building industry could start coping with resilience challenges – if the insurance industry compels it. Alex noted that some European designers have "re-skinned" commercial buildings with an entire new facade to gain the high-performance that was missing in the original building. “That's expensive, but one strategy to make an obsolete building far more sustainable and resilient at significantly less cost than tearing it down and starting over."

DM: What are the key messages you hope to share with the Building Resiliency Task Force, and what particular actions do you want the Task Force to take?AW: One of my messages is that resilience is about a lot more than flooding. We need to be creating residential buildings (multi-family apartments, row houses, single-family homes) that embody passive survivability--buildings that will maintain livable conditions even with extended loss of power or interruptions in heating fuel. This means changing the way they are built so that they have far better energy performance. We can build new homes or apartments that will never drop below 50°F even with no power or oil or gas heat. We can retrofit older homes and apartments to do that, but it's a lot harder and more expensive. The easy part is new construction; the far greater challenge is the existing building stock.DM: It seems that some people in the Bloomberg Administration get the need for resilience as well as energy efficiency and conservation. Where else do you see that awareness in NYC? In what NYC business or civic communities do you think it is especially important to raise awareness of the need for resilience? How can individuals help?I think the NYC chapter of the U.S. Green Building Council, Urban Green, has done a great job at raising awareness about resilience and sustainability. AIA New York and especially the Committee on the Environment (COTE) is also engaged in this. The number of well-known companies that are engaged in the Buildings Resiliency Task Force is very heartening: Durst, Albanese, and Tishman to mention a few. I don't know what role other organizations and companies will play in advancing resilience.DM: I’m sure that many Building Green publications have covered resilience applications specific to NYC. Can you share the links of any such articles for New Yorkers who want to take next steps in resilience?AW: This editorial from December 2005 introduced the concept of passive survivability and is available without logging into BuildingGreen.com, as much of our content is only accessible to subscribers. http://www.buildinggreen.com/auth/article.cfm/2005/12/1/Passive-Survivability/This article, from 2006, provided a more in-depth review of "passive survivability" as a design criterion for buildings, and it is also free:http://www.buildinggreen.com/auth/article.cfm/2006/5/3/Passive-Survivability-A-New-Design-Criterion-for-Buildings/On the RDI website I posted a ten-part series on the fundamentals of resilient design, though that would be a lot of links. Otherwise, you'd have to scroll through a dozen blogs in finding that series: